1. Field of the Invention
This invention relates to a client machine and a server machine that are mutually connected to each other through a network, and a contents delivery system which can confirm whether contents transmitted from the server machine are received by the client machine. This invention also relates to computer readable mediums respectively containing programs which instruct the client machine and the server machine to function as the contents delivery system.
2. Description of the Related Art
A client machine, which executes a WWW (World Wide Web) browser program, can retrieve HTML documents provided by a server machine that executes a WWW server program while the client machine is connecting to the server machine through a network such as LAN or Internet.
The client machine notifies the server machine of a URL to request an HTML document specified by this URL. In response, the server machine sends out the requested HTML document corresponding to the URL to the client machine. Upon receiving the HTML document, the client machine displays the HTML document on a screen through its browser.
However, after sending out the HTML document to the client machine, the server machine can not confirm whether the HTML document has actually been received by the intended client machine without problems. In other words, even if the server machine has sent out an HTML document to the client machine without any errors, only the client machine can recognize it. In order for the server machine to verify a normal reception of an HTML document at the client machine, the user of the client machine needs to operate the client machine to send out data indicating the conformation of the receipt to the server machine.
Thus, according to the above-mentioned conventional art, in order to confirm a data reception at the client machine side, the server machine had to rely on a manual operation by the user at the client machine. Accordingly, even when the data is received by the client machine successfully, the server could not confirm that the data were successfully received unless the user (receiver) notifies the server machine of the reception by performing an appropriate operation on the client machine. This procedure of confirmation is extra for the user. Thus, the convention art wants a simple and operable delivery confirmation system for data transmission.
To obviate the above-mentioned drawbacks in the conventional art, an object of the present invention is to provide a contents delivery system that enables a server machine to confirm whether contents sent from a server are successfully received by a client machine.
To achieve the above-mentioned object, the present invention provides the following construction.
A contents delivery system according to the present invention is equipped with a client machine that executes a client program capable of requesting delivery of contents and a server machine that has a storage for storing contents and executes a server program capable of transmitting the contents requested by the client machine to the client machine.
The server machine further includes an ID issuance part for issuing a delivery confirmation ID that is uniquely related to the contents requested by the client machine every time contents are requested by the client machine, a plug-in data creation part for creating plug-in data including the delivery conformation ID, client information which uniquely specifies the client machine and server information uniquely specifies the server machine, a plug-in data transmission part for transmitting the plug-in data including the delivery confirmation ID related to the contents that have been transmitted to the client machine by the server program, and a delivery confirmation receiving part for receiving delivery confirmation data. The client machine includes a delivery confirmation transmission part creating delivery confirmation data that include the delivery confirmation ID and the client information based upon the plug-in data including the delivery confirmation ID related to the contents that have been sent from the server program of the server machine and have been received by the client program, and transmitting the delivery confirmation data to the delivery confirmation receiving part of the server machine in accordance with the server information contained in the plug-in data.
With this construction, the server machine instructs the ID issuance part to issue a delivery confirmation ID corresponding to the contents when the server machine receives a request from the client machine to deliver the corresponding contents. The plug-in data creation part of the server machine then creates plug-in data including the delivery conformation ID, client information and server information. The client machine acquires the contents and the plug-in data, and instructs its delivery confirmation transmission part to create delivery confirmation data including the delivery confirmation ID and the client information that are included in the plug-in data. The client machine then transmits the delivery confirmation data to the delivery confirmation receiving part of the server machine through the delivery confirmation transmission part. Accordingly, the server machine can confirm that the contents related to the delivery confirmation ID have been received by the intended client machine by acquiring the delivery confirmation ID in the delivery confirmation data received by its delivery confirmation receiving part.